JPS63177159A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JPS63177159A JPS63177159A JP62009428A JP942887A JPS63177159A JP S63177159 A JPS63177159 A JP S63177159A JP 62009428 A JP62009428 A JP 62009428A JP 942887 A JP942887 A JP 942887A JP S63177159 A JPS63177159 A JP S63177159A
- Authority
- JP
- Japan
- Prior art keywords
- developing
- developing device
- toner
- drum
- image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005684 electric field Effects 0.000 claims abstract description 8
- 238000011161 development Methods 0.000 abstract description 25
- 238000012546 transfer Methods 0.000 abstract description 22
- 238000011109 contamination Methods 0.000 abstract description 2
- 238000007786 electrostatic charging Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 238000005513 bias potential Methods 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 241001122767 Theaceae Species 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
Landscapes
- Developing For Electrophotography (AREA)
- Color Electrophotography (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、複数の現像器を有し、所望の現像器を現像位
置に移動させて現像を行なう移動式の現像装置を利用し
た画像形成装置に関し、特に2色又は3仏具」−の中色
カラー又はフルカラー用の画像形成装置に好適に応用す
ることができる。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus that uses a mobile developing device that has a plurality of developing devices and performs development by moving a desired developing device to a developing position, and particularly relates to an image forming apparatus that uses a mobile developing device that has a plurality of developing devices and performs development by moving a desired developing device to a developing position. The present invention can be suitably applied to an image forming apparatus for medium color or full color of "3 Buddhist altar fittings".
′ “ びjljと
最近カラー画像形成装置等において、感光ドラム等の像
担持体の小型化、延いては装置全体の小型化等を目的と
して複数の現像器を例えば回転体に搭載し、該回転体を
駆動することにより所望の現像器を像担持体に対向した
現像位置へと移動させ、現像を行なう移動式の、例えば
回転式の現像装置が提案されている。Recently, in color image forming apparatuses and the like, a plurality of developing devices are mounted on a rotating body, for example, and the rotating body A mobile type, for example, a rotary type developing device has been proposed, in which a desired developing device is moved to a developing position facing an image carrier by driving a body to perform development.
回転式現像装置を適用したカラー画像形成装置において
は、感光ドラム上に形成されたWI像を現像するに際し
ては該感光ドラム上の潜像が現像位置を通過する以前に
現像装置の所望の現像器を現像位置へと移動させ、次い
で現像を行ない、その後該現像器は現像位置外へと移動
退避される。In a color image forming apparatus using a rotary developing device, when developing a WI image formed on a photosensitive drum, the latent image on the photosensitive drum is transferred to a desired developing device of the developing device before the latent image on the photosensitive drum passes through a developing position. is moved to the developing position, then development is performed, and then the developing unit is moved out of the developing position and retracted.
このような現像工程の中で1例えば現像ローラを使用し
磁気ブラシ現像を行なう現像器等では現像ローラ上に現
像剤が付着しているため現像器が現像位置への移動式現
像装置に至る前に現像剤が感光ドラムに接触し、所望の
現像域外にトナーが付着することがあった。又、現像終
了後現像器の退避時においても同様に、移動中現像ロー
ラに付着した現像剤が感光ドラムに接触し所望の現像域
外にトナーが付着することがあった。In such a developing process, 1. For example, in a developing device that uses a developing roller and performs magnetic brush development, developer adheres to the developing roller, so before the developing device reaches the mobile developing device to the developing position. In some cases, the developer came into contact with the photosensitive drum, causing toner to adhere outside the desired development area. Further, even when the developing device is retracted after the development is completed, the developer that has adhered to the developing roller during movement may come into contact with the photosensitive drum, and toner may adhere outside the desired development area.
このように感光ドラムの現像域外へと付着した茶所ψの
トナーは、転写紙を転写ドラムにまきつけて転写を行な
う画像形成装置においては転写ドラムの転写紙が巻付け
られていない領域を汚染したり、更には転写用帯電器等
をも汚染することになる。In an image forming apparatus that performs transfer by wrapping transfer paper around the transfer drum, the toner from the tea place ψ that adheres to the outside of the developing area of the photosensitive drum contaminates the area of the transfer drum where the transfer paper is not wrapped. Moreover, it may also contaminate the transfer charger and the like.
本発明者は、研究実験の結果、現像器の現像位置への移
動時及び現像位置からの離脱時に現像器から像担持体表
面方向へのトナーに対する反発電界を強めることにより
、像担持体への圧力によるトナーの付着、又は摺擦によ
るトナーの付着を阻止することでき、従来の上記間開を
解決し得ることを見出した0本発明は斯る新規な知見に
基づくものである。As a result of research and experiments, the present inventor has discovered that by increasing the repulsive electric field against toner from the developing device toward the surface of the image carrier when the developing device moves to the developing position and when leaving the developing position, It has been discovered that toner adhesion due to pressure or toner adhesion due to rubbing can be prevented, and the above-mentioned conventional spacing problem can be solved.The present invention is based on such novel findings.
衾」Lの」し頂
本発す1の1的は、複数の現像器を有し、所望の現像器
を現像位置に移動させて現像を行なう移動式現像装置に
おいて現像器の現像位置への移動時及び現像位置からの
離脱時に、像担持体への圧力によるトナーの付着又は摺
擦によるトナーの付着を阻止し、転写紙の汚れを防ぐほ
か、転写ドラム、転写4n電器等の諸機器の汚染を防止
し、高品質の画像を得ることのできる画像形成装置を提
供することである。Part 1 of this article is a method for moving a developing device to a developing position in a mobile developing device that has a plurality of developing devices and performs development by moving a desired developing device to the developing position. This prevents toner from adhering to the image carrier due to pressure or from rubbing when the image carrier is removed from the developing position, and prevents staining of the transfer paper, as well as contamination of various equipment such as the transfer drum and transfer 4n electric appliances. An object of the present invention is to provide an image forming apparatus that can prevent the above problems and obtain high-quality images.
!l!1 古 るための− 上記1的は本発明に係る画像形成装こにて達成される。! l! 1 - The first aspect mentioned above is achieved by the image forming apparatus according to the present invention.
要約すれば本発明は、複数の現像器を備え、所望の現像
器を現像位置に移動して像担持体上の潜像を現像する移
動式現像装置を有した画像形成装置にわいて、現像器の
現像位置への移動時及び現像位置からの離脱時において
、現像器からfIl担持体表面方向へのトナーに対する
反発電界を強めることを特徴とする画像形成装置である
。好ましい実施態様によると1反発電界は現像器への現
像バイアス印加電圧を制御することにより達成される。To summarize, the present invention relates to an image forming apparatus having a mobile developing device that includes a plurality of developing devices and moves a desired developing device to a developing position to develop a latent image on an image carrier. This image forming apparatus is characterized in that the repulsive electric field against the toner from the developing device toward the surface of the fIl carrier is strengthened when the device moves to the developing position and when the device leaves the developing position. According to a preferred embodiment, one repulsive power field is achieved by controlling the voltage applied to the developer bias to the developer.
111例
次に、本発明に係る画像形成装置を図面に即して更に詳
しく説明する。111 Example Next, the image forming apparatus according to the present invention will be explained in more detail with reference to the drawings.
第2図は1本発明を適用し得るレーザーカラープリンタ
ーの主要断面図を示す0本実施例において、潜像担持体
である感光ドラム1はプリント命令の信号に応じて矢印
方向に回転する。その周囲には帯電器2、レーザースキ
ャナー装置を有した露光手段3、回転式現像装置14、
転写f15、そしてクリーニング器6が配設されている
。又1回転式現像装置4はイエロートナーを用いるイエ
ロー現像器4Y、マゼンタトナーを用(するマゼンタ現
像器4M、シアントナーを用いるマゼンタ現像器4C1
そしてブラックトナーを用いるブラック現像器4Bを一
体に有する。各現像器は本願出願人による特公昭55−
20579号公報に開示がある如く、磁界の作用でトナ
ーの飛散を防+L L、図示の如く回転体4aに着脱可
能に保持され中心軸4bを中心に回転体4aと共に回転
移動し、現像位置に順次に配置される。一方、転写部5
はグリッパ5aを有した転写ドラム5bと、その内側に
配置された転写用帯電器5Cとを右する。FIG. 2 shows a main sectional view of a laser color printer to which the present invention can be applied. In this embodiment, a photosensitive drum 1, which is a latent image carrier, rotates in the direction of the arrow in response to a print command signal. Around it, a charger 2, an exposure means 3 having a laser scanner device, a rotary developing device 14,
A transfer f15 and a cleaning device 6 are provided. The one-rotation developing device 4 includes a yellow developer 4Y that uses yellow toner, a magenta developer 4M that uses magenta toner, and a magenta developer 4C1 that uses cyan toner.
It also integrally includes a black developing device 4B that uses black toner. Each developing device is manufactured by the applicant of the present application.
As disclosed in Japanese Patent No. 20579, the toner is prevented from scattering by the action of a magnetic field.As shown in the figure, it is removably held on a rotating body 4a, rotates around a central axis 4b together with the rotating body 4a, and moves to the developing position. Arranged sequentially. On the other hand, the transfer section 5
shows a transfer drum 5b having a gripper 5a and a transfer charger 5C disposed inside the drum 5b.
フルカラー画像の形成は従来のカラープリンターと同様
に、 l−記転写ドラム5上に支持した転写材I−に順
次色トナーを転写することで形成する。A full color image is formed by sequentially transferring color toners onto a transfer material I- supported on a transfer drum 5, as in conventional color printers.
斯る画像形成プロセスは当業者には周知であるのでこれ
以−1−詳しい説明は省略する。転写材はカセット7か
ら供給され、転写工程を終了した転写材は分離1没8に
より分離され、定着器9を経てトレイto、1:に至る
。Since such an image forming process is well known to those skilled in the art, a detailed explanation thereof will be omitted. The transfer material is supplied from a cassette 7, and the transfer material that has completed the transfer process is separated by a separation unit 8, passes through a fixing device 9, and reaches trays to and 1:.
第1図は回転式の現像装置の断面図を示すが、回転体4
aに搭載された各現像器は同じ構造とされるので、第2
図で現像位置に位置するイエロー現像器4Yのみが図示
される0図示されるように、現像器4Yは現fI!容器
11を備え、該現m容器11内は仕切板12により2つ
の部FAに分割されており、それぞれの部屋内にはスク
リュー13及び14が配設される。該スクリュー13.
14により現像剤りは現像容器11内で往復循環される
。一方、現像ローラ手段17は本実施例では、図示する
ように磁化された固定の磁石ローラ17aと、該磁石ロ
ーラ17aの周囲に図示矢印方向に回転自在に取付けら
れ、現像剤を搬送する現像スリーブ17bとから構成さ
れる。現像スリーブ17bの回転によりS1極でくみ上
げられた現像剤はドクターブレード18により搬送級が
規制されてN1極→sz +NZ 453極と搬送され
る。FIG. 1 shows a cross-sectional view of a rotary developing device.
Since each developing unit installed in a has the same structure, the second
In the figure, only the yellow developing device 4Y located at the developing position is shown. A container 11 is provided, and the inside of the current m container 11 is divided into two parts FA by a partition plate 12, and screws 13 and 14 are arranged in each room. The screw 13.
14, the developer is circulated back and forth within the developer container 11. On the other hand, in this embodiment, the developing roller means 17 includes a magnetized fixed magnetic roller 17a as shown in the figure, and a developing sleeve that is rotatably attached around the magnetic roller 17a in the direction of the arrow in the figure and conveys the developer. 17b. The developer pumped up at the S1 pole by the rotation of the developing sleeve 17b is conveyed in the order of N1 pole → sz +NZ 453 pole, with the transport level being regulated by the doctor blade 18.
N1極は現像主極であり、ここで穂立ちした現像剤が感
光ドラムl上の静電潜像を現像し、その後S3極、S1
極の反発磁界により現像スリーブ17b上の現像剤は現
像容器内へ落下する。ここで回転体以外の他の部所1例
えば装こ本体に現像バイアス電源51が設けられ、該バ
イアス電源51はリード線53を介して回転体の中心部
に、例えば回転体の固定中心軸4bに固定された所定長
さを有する電極54に電気的に接続される。該固定電極
は1本実施例では現像中心位置から、角度((7+、O
z)の範囲にわたって円孤状に延在して配置される。又
1本実施例では回転体と共に回転移動する現像器側に接
触子55が設けられ、該接触子55は前記電極54に接
触し、リード&a56を介して現像スリーブ17bに電
気的に接続される。従って、現像スリーブ17bには電
源51から電極54及び接触子55等を介して現像バイ
アスが印加iif能となる。The N1 pole is the main development pole, and the developer that stands up here develops the electrostatic latent image on the photosensitive drum l, and then the S3 pole and the S1
The developer on the developing sleeve 17b falls into the developing container due to the repulsive magnetic field of the pole. Here, a developing bias power source 51 is provided in a part other than the rotary body 1, for example, the loading body, and the bias power source 51 is connected to the center of the rotary body via a lead wire 53, for example, to the fixed central axis 4b of the rotary body. It is electrically connected to an electrode 54 having a predetermined length fixed to . In this embodiment, the fixed electrode is arranged at an angle ((7+, O
z). Further, in this embodiment, a contact 55 is provided on the side of the developing device that rotates together with the rotating body, and the contact 55 contacts the electrode 54 and is electrically connected to the developing sleeve 17b via a lead &a 56. . Therefore, a developing bias can be applied to the developing sleeve 17b from the power source 51 via the electrode 54, the contact 55, etc.
第3図は、現像器が現像位置へと接近し又現像位置から
離脱するときの現像ローラ17.1tt極54及び接触
子55の関係を図示するものであり、該第3図をも参照
するとより良く理解されるように、′電極54は現像器
4Yの移動軌跡に沿って。FIG. 3 illustrates the relationship between the developing roller 17.1tt pole 54 and the contact 55 when the developing device approaches and leaves the developing position, and FIG. 3 is also referred to. As can be better understood, the 'electrode 54 follows the movement trajectory of the developing device 4Y.
ここでは現像位置に至る01手前から現像器4Yの移動
とJ(に接触しはじめ接触子55と電極54は接触を維
持したまま移動し、現像絆了後現像器が電極54と離間
するO2のときに、接触子55と電極54は接触子の接
触が離れる。このように、接触子55と′准極54とは
現像位置を境に「前に01、離脱方向にθこの範囲内に
て電気的に接続されるので、現像スリーブ上の現像剤は
、現像位置の前後において現像バイアスを印加すること
ができる。Here, the developing device 4Y moves from 01 before reaching the developing position and starts contacting the contactor 55 and the electrode 54, and moves while maintaining contact, and after the development is completed, the developing device separates from the electrode 54. When the contact 55 and the electrode 54 are out of contact with each other, the contact 55 and the quasi-pole 54 are separated from each other by 01 in the front and θ in the detachment direction from the developing position. Since it is electrically connected, a developing bias can be applied to the developer on the developing sleeve before and after the developing position.
第4図には本実施例におけるドラムの表面電位が説明さ
れる0画像形成に当り、−次帯電器2によりドラム表面
は一様にVd (−650V)に帯電され、レーザー光
の照射された部分aは、表面電位が7文(−150V)
まで低下する。FIG. 4 shows the surface potential of the drum in this example. During zero image formation, the drum surface was uniformly charged to Vd (-650V) by the -order charger 2 and irradiated with laser light. Part a has a surface potential of 7 (-150V)
decreases to
次いで、現像時においてマイナス(−)に帯電されたト
ナーが現像バイアスWb (−500V)の中下のもと
でドラム表面に供給されると、ドラム表面のaの部分に
付着し、現像が行なわれる。Next, during development, when the negatively charged toner is supplied to the drum surface under a mid-low developing bias Wb (-500V), it adheres to the portion a of the drum surface and development is performed. It will be done.
つまり、現像時Vl−Vb=VC(350V)(7)コ
ントラスト電位の中でトナーが、ドラムへ静電吸着され
る。中間調を再現するにはレーザー光を変調することに
よって、又はVCを制御することによってドラムへのト
ナー付着量がコントロールされる。That is, during development, Vl-Vb=VC (350V) (7) The toner is electrostatically attracted to the drum in the contrast potential. To reproduce halftones, the amount of toner adhering to the drum is controlled by modulating the laser beam or by controlling VC.
レーザー光の照射されない部分は、ドラム表面電位Vd
が維持されるためトナーは付着されず白地となる。しか
しながら、現像器の現像位置への移動時及び現像位置か
らの離脱時には、像担持体と現像ローラとの接触に起因
する像担持体への圧力によるトナーの付着、又は摺擦に
よるトナーの付着を起し易いという傾向がある。The part not irradiated with the laser beam has a drum surface potential Vd
is maintained, so toner is not attached and the background becomes white. However, when the developing device moves to and leaves the developing position, toner may adhere to the image bearing member due to pressure caused by contact between the image bearing member and the developing roller, or toner may adhere due to rubbing. There is a tendency to wake up easily.
本発明に従えば、現像器の現像位置への移動時及び現像
位置からの離脱時において、ドラム表面をVd (−6
50V)に維持し、現像バイアス■dは現像時の一50
0Vより一350Vまでドげ、Vd−Vb=300Vの
電位差を設はマイナス(−)トナーに対してドラム表面
をマイナス方向の電位差を増すことによってトナーの付
着を防ぐ構成とされる。つまり、本発明に従えば現像器
の現像位置への移動時及び現像位置からの離脱時におい
て、現像器から感光ドラム表面方向へのトナーに対する
反発電界を強めることにより感光ドラム表面への現像器
からのトナーの付着が防1トされる。According to the present invention, when the developing unit moves to the developing position and when leaving the developing position, the drum surface is set at Vd (-6
50V), and the developing bias d is -50V during development.
By setting a potential difference of Vd-Vb=300V from 0V to -350V, the drum surface is configured to prevent toner from adhering by increasing the potential difference in the negative direction on the drum surface with respect to negative (-) toner. In other words, according to the present invention, when the developing device is moved to the developing position and when the developing device is removed from the developing position, the repulsive electric field against the toner from the developing device toward the photosensitive drum surface is strengthened. toner adhesion is prevented.
第5図は、本発明に従って反発電界を付!トする際のタ
イムチャートを示す、先ず、タイミングFにて付勢され
た一次帯′i1を器2によりドラム表面はVdに維持さ
れる0次いで、現像位置から離間していた現像器がタイ
ミングAで移動を開始し、タイミングBで現像位置へと
移動を終了する。この移動時、第3図に図示したように
接触子55が電極54に乗り上げ、その後現像ローラ手
段17上のトナーが感光ドラムに接触する前のタイミン
グGにて現像器には現像バイアスが印加される。FIG. 5 shows a repulsive power field according to the present invention. First, the drum surface is maintained at Vd by the device 2 when the primary band 'i1 is energized at timing F. Then, the developing device that has been separated from the developing position is moved to timing A. It starts moving at timing B, and ends moving to the developing position at timing B. During this movement, the contactor 55 rides on the electrode 54 as shown in FIG. 3, and a developing bias is applied to the developing device at timing G before the toner on the developing roller means 17 comes into contact with the photosensitive drum. Ru.
現像器が移動を完了し、現像位置に設定された後、該現
像器はドラムの回転に合わせてタイミングDからEまで
の間、現像に必要な駆動力が供給される。現像が終了す
ると、該現像器はタイミングCで現像位置より退避位置
へと離脱させるために移動を開始する。この移動時にも
やはり現像ローラ手段、つまり現像スリーブ上のトナー
がドラムに接触している間は現像バイアスは印加され続
け、トナーとドラムが完全に離れた後タイミング■(で
現像バイアスの出力は停止される。After the developing device completes its movement and is set at the developing position, the driving force necessary for development is supplied to the developing device from timing D to E in accordance with the rotation of the drum. When the development is completed, the developer starts moving at timing C to move away from the development position to the retracted position. During this movement, the developing bias continues to be applied while the developing roller means, that is, the toner on the developing sleeve is in contact with the drum, and after the toner and drum are completely separated, the output of the developing bias is stopped at timing be done.
上記タイミングGよりHまでの現像バイアスは、現像に
必要な現像電位を与えるための時間t2と、不必要なト
ナーのドラム付着を防ぐための′−L位を11えるため
の時間t、、t3に分られ、現像バイアス′心源51の
Itj力は第6図に図示する如くに制御される。つまり
、上述したように、現像バイアスvbはtl、tl時に
は−350Vニ。The development bias from the timing G to H is the time t2 for applying the development potential necessary for development, and the time t, t3 for increasing the '-L position by 11 to prevent unnecessary toner from adhering to the drum. The developing bias and the Itj force of the center source 51 are controlled as shown in FIG. That is, as mentioned above, the developing bias vb is -350V at tl and tl.
tz時には一5oovとされる。At tz time it is 15oov.
に記実施例の説明では、複数の現像器を回転する回転体
に搭載した回転式の現像装置を有した画像形J&装置に
ついて説151 したが1本発明の原理は、現像34Y
、4M、4C,4Bを1llilえた現!装置4を直線
的に左右、上下に移動し所望の現像器を現像位置に位置
せしめる構成の現像装置や、現像器4Y、4M、4C1
4Bを備えた現像装置4を回転移動及び直線移動により
所望の現像器を現像位置に配置する構成の現像器を等に
も同様に適用することができる。In the description of the embodiment described in 151, an image-forming J& apparatus having a rotary developing device in which a plurality of developing devices are mounted on a rotating body is described.151 However, the principle of the present invention is that
, 4M, 4C, and 4B now! A developing device configured to move the device 4 linearly left and right, up and down to position a desired developing device at a developing position, and developing devices 4Y, 4M, and 4C1.
The present invention can be similarly applied to a developing device having a configuration in which a desired developing device is placed at a developing position by rotating and linearly moving the developing device 4 provided with the developing device 4B.
i且立盪]
以上説明したように、本発明に係る画像形成装置は、現
像器の現像位置への移動時及び現像位置からの離脱時に
現像器から像担持体表面方向へのトナーに対する反発電
界を強めることにより、像担持体への圧力によるトナー
の付着、又は摺擦によるトナーの付着を阻1トすること
でき、転写紙の7rJれを防ぐほか、転写ドラ、ム、転
写帯電塁等の画像形成装置内の品機器を汚染させること
がなく良&fな画像を得ることができる。As described above, the image forming apparatus according to the present invention generates a repulsive electric field against the toner from the developing device toward the surface of the image carrier when the developing device moves to the developing position and when the developing device leaves the developing position. By increasing the pressure, it is possible to prevent toner from adhering to the image bearing member due to pressure or due to friction, and in addition to preventing the transfer paper from becoming 7rJ, it also prevents the transfer drum, drum, transfer charging base, etc. Good quality images can be obtained without contaminating equipment within the image forming apparatus.
第1図は、本発明に従った画像形成装置の回転式現ft
!A21部分の部分断面図である。
第2図は、本発明に従ったレーザーカラープリンターの
断面図である。
第3図は、現像器が現像位置へと接近し又現像位置から
離脱するときの現像ローラ、電極及び接触子の関係を図
示する説明図である。
第4図は1本発明に従って印加される像担持体上の電位
と、現像バイアス電位との関係を示す図である。
第5図及び第6図は、本発明に従って構成される画像形
成装置の作動タイミングチャート及び印加される現像バ
イアス電位の制御タイミングチャートを示す図である。
l:像担持体
4:回転式現像装置
17:現像ローラ
51:バイアス電源
54:電極
55:接触子
代理人 弁理士 倉 橘 暎 、?テ7.’、
’シ。
第4図
第5図FIG. 1 shows a rotary model of an image forming apparatus according to the present invention.
! It is a partial sectional view of the A21 part. FIG. 2 is a cross-sectional view of a laser color printer according to the invention. FIG. 3 is an explanatory diagram illustrating the relationship among the developing roller, electrodes, and contacts when the developing device approaches and leaves the developing position. FIG. 4 is a diagram showing the relationship between the potential applied on the image carrier and the developing bias potential according to the present invention. FIGS. 5 and 6 are diagrams showing an operation timing chart of an image forming apparatus configured according to the present invention and a control timing chart of a developing bias potential to be applied. l: Image carrier 4: Rotary developing device 17: Developing roller 51: Bias power source 54: Electrode 55: Contact agent Patent attorney Akira Kura Tachibana,? Te7. ',
'S. Figure 4 Figure 5
Claims (1)
動して像担持体上の潜像を現像する移動式現像装置を有
した画像形成装置において、現像器の現像位置への移動
時及び現像位置からの離脱時において、現像器から像担
持体表面方向へのトナーに対する反発電界を強めること
を特徴とする画像形成装置。 2)現像器への現像バイアス印加電圧を制御することに
より現像器から像担持体表面方向へのトナーに対する反
発電界を強めるようにした特許請求の範囲第1項記載の
装置。[Scope of Claims] 1) In an image forming apparatus having a mobile developing device which includes a plurality of developing devices and which develops a latent image on an image carrier by moving a desired developing device to a developing position, the developing device An image forming apparatus characterized in that a repulsive electric field against toner from a developing unit toward the surface of an image carrier is strengthened when the image forming apparatus moves to a developing position and when leaving the developing position. 2) The apparatus according to claim 1, wherein the repulsive electric field against the toner from the developing device toward the surface of the image carrier is strengthened by controlling the developing bias voltage applied to the developing device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62009428A JPS63177159A (en) | 1987-01-19 | 1987-01-19 | Image forming device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62009428A JPS63177159A (en) | 1987-01-19 | 1987-01-19 | Image forming device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS63177159A true JPS63177159A (en) | 1988-07-21 |
Family
ID=11720063
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62009428A Pending JPS63177159A (en) | 1987-01-19 | 1987-01-19 | Image forming device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS63177159A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08171269A (en) * | 1994-10-21 | 1996-07-02 | Ricoh Co Ltd | Image forming device |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61120174A (en) * | 1984-11-15 | 1986-06-07 | Canon Inc | Image forming device |
JPS61243471A (en) * | 1985-04-20 | 1986-10-29 | Canon Inc | Developing device |
-
1987
- 1987-01-19 JP JP62009428A patent/JPS63177159A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61120174A (en) * | 1984-11-15 | 1986-06-07 | Canon Inc | Image forming device |
JPS61243471A (en) * | 1985-04-20 | 1986-10-29 | Canon Inc | Developing device |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08171269A (en) * | 1994-10-21 | 1996-07-02 | Ricoh Co Ltd | Image forming device |
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